ignore invalid values in arccos calculation

Ouranosinc · Oct 6, 2023 · 19dc5a2 · 19dc5a2
1 parent 2665a6f
commit 19dc5a2
Showing 1 changed file with 4 additions and 3 deletions.
diff --git a/xclim/indices/helpers.py b/xclim/indices/helpers.py
@@ -429,9 +429,10 @@ def day_lengths(
     lat = convert_units_to(lat, "rad")
     # arccos gives the hour-angle at sunset, multiply by 24 / 2π to get hours.
     # The day length is twice that.
-    day_length_hours = (
-        (24 / np.pi) * np.arccos(-np.tan(lat) * np.tan(declination))
-    ).assign_attrs(units="h")
+    with np.errstate(invalid="ignore"):
+        day_length_hours = (
+            (24 / np.pi) * np.arccos(-np.tan(lat) * np.tan(declination))
+        ).assign_attrs(units="h")
 
     return day_length_hours